Field of the Invention
The aspect of the embodiments relates to an image pickup apparatus, and more particularly, to an image pickup apparatus having a function for adjusting an in-focus position detected by focus detection, and a control method for the image pickup apparatus.
Description of the Related Art
In an image pickup apparatus, so-called focus adjustment for automatic focus adjustment has heretofore been known. Focus adjustment is a technique of detecting the individual differences of parts to be used due to tolerances in production or the like, storing, in advance, adjustment values for automatic focus adjustment according to the respective operation characteristics in a non-volatile memory at the time of shipping from a factory, and performing appropriate focus adjustment based on the adjustment values.
On the other hand, there are circumstances in which components are worn due to, for example, a long-period use, in a use environment of a user, and optical components are misaligned in a specific environment, for example, under high temperature or low temperature. In addition, in an image pickup apparatus to which an interchangeable lens unit is attached, an in-focus position may deviate from that at the time of shipping from a factory, depending on a combination of the lens unit and the image pickup apparatus.
In this regard, a technique for storing an adjustment value set by a user in a main body portion separately from adjustment values stored in a non-volatile memory at the time of shipping from a factory is known. According to this technique, an adjustment value (AF adjustment value) for focus adjustment can be set by a user.
For example, Japanese Patent Application Laid-Open No. 2011-232704 discusses a technique for calculating the AF adjustment value from a difference between a defocus amount detected using a dedicated AF sensor and a defocus amount detected using an image sensor that outputs a captured image signal. This method enables a user to set the AF adjustment value more easily than in the case of setting an arbitrary AF adjustment value.
However, in the focus detection using a pixel signal discussed in Japanese Patent Application Laid-Open No. 2011-232704, detection results may vary depending on the brightness or contrast of a subject, or no detection results may be obtained. Therefore, it is not always preferable to follow the focus detection result of the pixel signal in the calculation of the adjustment value.
Therefore, an image pickup apparatus of acquiring an adjustment value with a high accuracy even when results of focus detection using a pixel signal vary is sought.